JPEG files are compressed image files. They support 24-bit color and have been a popular choice for use on the web because JPEG file size is often substantially smaller than many other image formats. However, the JPEG compression algorithm is lossy and is not recommended for most map images, as line drawings and text or iconic graphics become blurred by compression artifacts. Thus, PNG is usually a superior format for map images. JPEGs exported from the data view in ArcMap can be generated with an accompanying world file for use as georeferenced raster data.
